CVE-2026-11793

A stack buffer overflow flaw was found in 389 Directory Server. The checkPrefix() function in pw.c copies an attacker-controlled algorithm ID into a 256-byte stack buffer without bounds checking when parsing reversible-encrypted attribute values. An attacker with Directory Manager privileges can crash the LDAP server by storing a crafted credential with an oversized algorithm ID. FORTIFY_SOURCE mitigates this to denial of service only.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Restrict Directory Manager access. Monitor cn=config attributes (nsDS5ReplicaCredentials, nsDS5ReplicaBootstrapCredentials) for abnormally long values. Restrict LDAP administrative access to management networks or localhost (LDAPI).